I don't think there's any indication that Jian-Yang did this - he leaves the party immediately he realizes that Erlich is now wealthy and is a better "mark" than Pied Piper. Also, that was the final episode - so no more seasons.
– iandotkelly♦Dec 10 '19 at 19:57

@iandotkelly: It was also shown that Jian-Yang was somewhere in Asian country ( probably phillipines) with some estate and luxurious cars and personal bodyguards. When he left he was kind of poor. So where did all that fortune came from ? Maybe he stole and sold in China.
– RahulDec 10 '19 at 20:27

1

The real question is why is Richard such a thumbass?
– shimDec 11 '19 at 17:24

@shim: Because he kept a billion dollar tech on a thumb drive. ☺
– RahulDec 11 '19 at 18:35

3 Answers
3

The episode — and series — ends with a cliffhanger of sorts as Richard is unable to find the thumb drive. What did you like about going in that direction? Was it your way of leaving the door open for a continuation in the future, or just more of a fun little thing for fans to theorize about?

I will be perfectly candid that we have no grand plan to return, but we were joking about it, like, “Oh, that’s the Silicon Valley movie, the search for the thumb drive.” We just like the idea that they create this doomsday device and then, in the end, Richard forgot where he put it. It just seemed like a funny place to end. But if it leads to something… look, I love this cast and I love this show, and if there were an opportunity at some point and it felt right to do more with them, I’d do it in a heartbeat. But there are no plans to do that, and that was not the design or seed of any new project…until it is!

Unknown but not Jian-Yang

It's not revealed who (if anyone) has taken the thumb drive. I think the missing thumb drive is just meant to show that Richard still is not entirely in control, and there still is some danger than someone else may release the Pied Piper AI on the world.

However it's very unlikely to be taken by Jian-Yang. Jian-Yang is impersonating Erlich Bachman and looks like he has taken all his money.

We can see this from the conversation between Richard, Monica and Jian-Yang at the party:

Jian-Yang: Richard, congratulations. It's your very close friend Jian-Yang, and I would like you to give me free shares of Pied Piper.

Richard: Okay, Jian-Yang. Uh well, you had plenty of opportunity to invest.

Monica: Still do. Yeah, you can buy Pipercoin.

Jian-Yang: Monica, two men are talking business. You can find your broom and fly away.

Monica: Suit yourself. I just checked the ledger, and the coin we issued to Erlich was just sold for $20 million.

Jian-Yang: Richard, is the mean lady right? Errich is now fat and rich?

Richard: Uh, yeah, I guess.

Jian-Yang: Where is he?

Richard: I don't know. Tibet still, maybe.

Jian-Yang immediately walks off and discards his Pied Piper hat on the floor.

Then at the end of the episode, when the documentary crew try to reach Erlich:

Interviewer: Are you Erlich Bachman?

Jian-Yang: Yes. I'm Errich Bachman. I can show you ID. That's my face.
I was a-fat, but now, I'm a-not fat.

The implication of this scene is that Jian-Yang is rich off Erlich's $20 million, not somehow off the thumb-drive.

Will there be more seasons about the missing drive?

S06E07 Exit Event was advertised as the Series Finale, and much took place as a documentary 10 years into the future. It seems likely that there will be no more episodes.

While the OP's question invites speculation, I find your theory plausible. Gilfoyle shouldn't have had any difficulty air-gapping a running copy of the evolved AI and ethics doesn't seem to be that much of an issue for any of the three you've mentioned.
– user18935Dec 11 '19 at 12:25

There isn't any reason to believe Monica, Dinesh or Gilfoyle stole it. They could have all potentially made their own copies if they wanted (and they probably do have their own copies), and they're all aware of the danger it poses, and presumably Richard didn't even tell them he had it. It's most likely just intentionally ambiguous.
– shimDec 11 '19 at 17:19